31469-89-3Relevant academic research and scientific papers
Synthesis of nitrophenyl and fluorophenyl azides and diazides by SNAr under phase-transfer or microwave irradiation: Fast and mild methodologies to prepare photoaffinity labeling, crosslinking, and click chemistry reagents
Leyva, Elisa,Aguilar, Johana,González-Balderas, Regina M.,Vega-Rodríguez, Sarai,Loredo-Carrillo, Silvia E.
, (2020/12/01)
Two fast and mild methodologies to prepare nitrophenyl and fluorophenyl azides are presented. These aryl azides are extensively used as crosslinking, photoaffinity labeling, and click chemistry reagents. Substituted aryl azides are prepared by performing a SNAr substitution on halogenated benzenes with a phase-transfer catalyst (PTC) such as tetraethylammonium tetrafluoroborate (TEATFB), the reaction proceeds in several hours under rather mild temperatures (25°C to 70°C). Furthermore, aryl azides are also prepared within minutes under microwave irradiation at slightly higher temperatures (50°C to 70°C). These procedures could be applied in the preparation of other aryl azides. In the case of substituted pentafluoro benzene (pF), the type of products obtained in each reaction depends on the amount of sodium azide and the strength and position of electron-withdrawing substituents (COH, COR, COOR, CN, NO2, or F). A discussion on the mechanisms and the products obtained in these SNAr reactions is presented.
Iron (III)-porphyrin Complex FeTSPP as an efficient catalyst for synthesis of tetrazole derivatives via [2?+?3]cycloaddition reaction in aqueous medium
El-Remaily, Mahmoud Abd El Aleem Ali Ali,Elhady
, (2019/06/08)
The metal complex (5,10,15,20-tetrakis-(4-sulfonatophenyl)-porphyrin-iron (III) chloride (FeTSPP) was new employed in an environmentally benign protocol as an efficient catalyst for a “click” chemistry approach for the synthesis of tetrazole and guanindinyltetrazole derivatives via [2?+?3] cycloaddition reaction of nitriles and azide derivatives in aqueous medium. The synthesized compounds were obtained in excellent yield, short reaction times and a recoverable catalyst.
N, N -diethylurea-catalyzed amidation between electron-deficient aryl azides and phenylacetaldehydes
Xie, Sheng,Ramstr??m, Olof,Yan, Mingdi
supporting information, p. 636 - 639 (2015/03/04)
Urea structures, of which N,N-diethylurea (DEU) proved to be the most efficient, were discovered to catalyze amidation reactions between electron-deficient aryl azides and phenylacetaldehydes. Experimental data support 1,3-dipolar cycloaddition between DEU-activated enols and electrophilic phenyl azides, especially perfluoroaryl azides, followed by rearrangement of the triazoline intermediate. The activation of the aldehyde under near-neutral conditions was of special importance in inhibiting dehydration/aromatization of the triazoline intermediate, thus promoting the rearrangement to form aryl amides.
1,3-Dipolar cycloaddition reactivities of perfluorinated aryl azides with enamines and strained dipolarophiles
Xie, Sheng,Lopez, Steven A.,Ramstr?m, Olof,Yan, Mingdi,Houk
supporting information, p. 2958 - 2966 (2015/03/18)
The reactivities of enamines and predistorted (strained) dipolarophiles toward perfluoroaryl azides (PFAAs) were explored experimentally and computationally. Kinetic analyses indicate that PFAAs undergo (3 + 2) cycloadditions with enamines up to 4 orders of magnitude faster than phenyl azide reacts with these dipolarophiles. DFT calculations were used to identify the origin of this rate acceleration. Orbital interactions between the cycloaddends are larger due to the relatively low-lying LUMO of PFAAs. The triazolines resulting from PFAA-enamine cycloadditions rearrange to amidines at room temperature, while (3 + 2) cycloadditions of enamines and phenyl azide yield stable, isolable triazolines. The 1,3-dipolar cycloadditions of norbornene and DIBAC also show increased reactivity toward PFAAs over phenyl azide but are slower than enamine-azide cycloadditions.
Highly selective synthesis of 1-polyfluoroaryl-1,2,3-triazoles via a one-pot three-component reaction
Cao, Liming,Liu, Cuibo,Tang, Xiangyang,Yin, Xuguang,Zhang, Bin
supporting information, p. 5033 - 5037 (2015/01/08)
A series of 1-polyfluoroaryl-1,2,3-triazoles were synthesized in moderate to good yields by an efficient copper-catalyzed one-pot three-component reaction of polyfluoroarenes, sodium azide, and terminal alkynes. The method involves a polyfluoroarylated azide intermediate produced in situ by the selective CF bond cleavage of polyfluoroarene with sodium azide.
Microwave-assisted synthesis of substituted fluorophenyl mono- and diazides by SNAr. A fast methodology to prepare photoaffinity labeling and crosslinking reagents
Leyva, Elisa,Leyva, Socorro,Moctezuma, Edgar,González-Balderas, Regina M.,De Loera, Denisse
, p. 164 - 169 (2013/11/19)
The reaction of sodium azide with perfluorobenzene, containing an electron-withdrawing group, under microwave irradiation results in the fast preparation of p-substituted tetrafluorophenyl monoazides. Having an excess of sodium azide and a strong electron-withdrawing group like NO2 or CN, fluorophenyl diazides are also produced upon conventional or microwave heating. A synergic effect between the amount of sodium azide and the electron-withdrawing character of the substituents is observed giving different products. A discussion on the products and reaction mechanism is presented.
